The CHP submitted an application to annul Sunday's vote, objecting to the electoral board's decision to allow unstamped ballots. Turkey's Supreme Electoral Council will hear objections against Sunday's referendum today.
The main opposition, including the Republican People's Party or the CHP, began a battle on Tuesday to annul the referendum which agreed to change Turkey's system of governance to an executive presidency.
The head of Turkey's Supreme Electoral Council issued a short statement on Wednesday saying they will evaluate objections to Sunday's referendum.
The Union of Turkish Bar Associations (TBB) said what it considers an illegal move by electoral authorities may have swung the vote.
The bar association said a last-minute decision by the electoral board to allow unstamped ballots in the referendum was clearly against the law and prevented proper records from being kept.
The government has responded by saying that there was no foul play and that the results are legitimate.
TRT World 's Hasan Abdullah has more from Ankara.